Printing mechanism.



C. P. CTTRELL.

PRINTING MEGHANISM.

APPLIOATION FILED JUNE 27, 1911.

G. P. GOTTRELL.

PRINTING MEGHANISM.

APPLICATION FILED JUNE 27, 1911..

2 SHEETS-SHBET 2.

Patented Ma?. 2, 1915.

UNITED sTATEs PATENT OFFICE.

CHARLES I. COTTRELL, OF WESTERLY, RHODE ISLAND, ASSIGNOB, BY MESNE ASSIGN- MENTS, T0 C. B. COTTRELL &; SONS COMPANY, 0F NEW YORK, N. Y., A CORPORATION 0F DELAWARE.

Application lcd June 27, 1911.

To all lwhom it may concern Be it known that I, CHARLES-P. COTTRELL, a citizen of the United States, and resident of Westerly, in the county of Washington and State of Rhode Island, have invented a new and useful Improvement in Printing Mechanism, of which the following is a specification.

This invention relates to gearing for rotary printing machines and has for its object to so arrange the plate cylinder that it will be permitted a limited rotary movement with respect to its gear whereby the movement of the plate cylinder during the printing operation will be under the control of the plate; novel means being employed for automatically bringing the plate cylinder into proper register with the impression cylinder at a predetermined portion of the rotary movement of said cylinder and locking the cylinder in such proper register to its gear after the completion of the printing operation, preferably at the beginning of said printing operation, said cylinder being immediately released to permit the printing operation to be continued without being influenced by its gear connection with the impression cylinder.

In the accompanying drawings, I have shown the invention as applied to a multicolor rotary printing machine.

Figure 1 represents in partial side elevation so much of a four-color rotary printing machine as will give a clear understanding of my invention. Fig. 2 is a partial end view of the same, Fig. 3 is a detail section showing the parts in the position which they assume when the plate cylinder is locked to its gear at the beginning of the printing operation, and Fig. 4 is a similar View with the parts in the position which they assume when the plate cylinder is released from its gear and has traveled 180 from the position shown in Fig. 3.

The side framing of the machine is denoted by 1. The impression cylinder by 2 and each of the plate cylinders by 3. The impression cylinder gear 'is denoted-by 4, which gear may be driven from a gear 5 on the driving shaft 6. The plate cylinder gears driven from the impression cylinder gear 4 are denoted by 7 and their stationary 'controlling cams by 8, which cams are herein shown as' carried by the side framing 1Y PRINTING MECHANISM.

Patented Mar. e, 1915.

Serial N o. 635,621.

cylinder 3, lwhich lever is provided with acani roller 11 arranged to pass through the stationary cam 8 during the rotation of said plate cylinder.

Means are provided for bringing the plate cylinder into proper register and for locking the plate cylinder to and releasing it from its gear, which means may comprise a wedge 12 on the cam lever 9, arranged to be brought into and out of locking engagement with vseats 13, 14, formed, in the present instance, by blocks secured tothe plate cylinder gear 7, said wedge being so arranged that when the cam roller 11 on the cam lever 9 is moved outwardly bythe cam 8 the cylinder 3 will be locked to the gear 7 and when moved inwardly the cylinder will be permitted a limited rotary movement with respect to its gear.

The bolts l5 which secure the gear 7 to the end of the plate cylinder pass through enlarged holes`16 in the gear so as to permit this limited rotary movement of the cylinder in either direction while the gear is held close to the end of the cylinder.

A spring device 17 carried bythe cylinder serves to normally swing the cam lever 9 and its roller inwardly.

In operation: presupposing the parts to be in the position shown in Fig. 3, with the plate cylinder locked to its gear, the form on the plate cylinder being in position to start the printing operation: As soon as the printing operation has begun. the cam 8 will, because of its engagement with the roller 11, rock the lever 9 inwardly thus withdrawing the wedge `12 out of contact with its seats 13, 14, thus leaving the cylinder 3 free to move rotatively to a limited extent with respect to its gear 7. The travel of the plate cylinder is then controlled entirely by the vform thereon without being influenced by the gear connection between the impression and plate cylinders. Aitor the printing op- -eration has been completed, the continued rotary movement of the plate cylinder will canse the stationary cam 8, because of its engagementvrith the roller 11, to move the lever 9 outwardly against the tension of its spring device 17 and bring the wedge 12 into locking engagement with the seats 13, 11. This movement will, at every revolution of the plate cylinder, bring it into absolute register with its impression cylinder just before the next succeeding printing opl eration is started. ,lt will thus be seen that the plate and impression cylinders must always be brought into the same relative positions bel'ore each successive printing operation, the printing operation itself being carried on while the plate cylinder is free to move independent ot the geared eonneetimrwith the impression cylinder and by the frictional contact oi' its form with the impression cylinder.

Thefreleasing olE the plate cylinder gear to permit the plate cylinder a limited free movement in either direction, gives the pressman a great deal more latitude for maling ready the form than where this is not done. It the form is high. the tendency is for the plate cylinder to drop back i slightly during the printing operation. It the form is low, the plate cylinder will run slightly ahead during the printing operation. This loss or gain in the travel of the plate cylinder is corrected for the next sue#` cessive printing operation by bringing the cylinder into register and locking the cylinder to its driving gear as hereinabove set forth. is controlled entirely by the form during the printing operation, a slight variation As the travel of the plate cylinder.

in the height of the plates and backing does not destroy any ot' the plate values.

It is evident that slight changesmight be resorted to in the form,'construction and arrangement ot' the several parts Without de parting from the spirit and scope of my inventlon; hence I do not Wish to limit myself strictly tothe structure herein Vset forth, but

YV hat I claim iszl. Printing mechanism including a gear,

a plate cylinder having a limited rotary movement with respect thereto, a statlonary cam, a rocking lever carried by the cylinder and a wedge on the rocking lever moved by said cam into engagement with the gear for bringing the cylinder into register therewith.

2. Printing mechanism including a gear, a plate cylinder having a limited rotary movement with respect thereto, a stationary cam, seats on the gear, a rocking lever earried by the cylinder and a wedge on the rocking lever moved by said cam into locking position between said seats for bringing the cylinder into register with said gear.

3. Printing mechanism including a gear, a plate cylin .ler, means` for securing the gear to the cylinder with a limited rotative lost motion, a stationary cam and means carried 

